use new version of flamegraph

flamegraph-rs/flamegraph#95 has landed and
there's a new version with it released.

fantoch_exp/exp_files/setup.sh

@@ -86,18 +86,7 @@ setup() {
         fi
 
         # install flamegraph
-        # TODO go back to 'cargo install flamegraph' once https://github.com/flamegraph-rs/flamegraph/pull/95 gets merged
-        if [[ ! -d ~/flamegraph ]]; then
-            until git clone https://github.com/vitorenesduarte/flamegraph ~/flamegraph; do
-                echo "git clone failed; trying again"
-                rm -rf ~/flamegraph
-            done
-        fi
-        cd ~/flamegraph
-        git checkout perf.data
-        cargo install --path .
-        cd -
-
+        cargo install flamegraph
         flamegraph --help
         ;;
     "heaptrack")